{"id":"F2006B03585","name":"AD/BEA 121/20 - Throttle Cable Assembly","slug":"ad-bea-121-20-throttle-cable-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43157,"registerId":"commonwealth-F2006B03585-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEA 121/20 - Throttle Cable Assembly","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Beagle B121 (Pup) Series Aeroplanes\n\n \n\nAD/BEA 121/20 Throttle Cable Assembly 4/78\n\nApplicability: All model B121 Series 2 and 3.\n\n \n\nRequirement: Replace throttle cable assembly P/N BE.47.20017 with P/N BE.47.20037 for Series 2 aircraft and P/N BE.47.30019/1 with P/N BE.47.30025 for Series 3 aircraft.\n\n \n\nNote: Scottish Aviation SB No. B121/74 also refers.\n\n \n\nCompliance: Before 31 May 1978.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive with a narrow, specific scope (throttle cable replacement on two specific aircraft series). It has not expanded beyond its original purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined part numbers per aircraft series (4 total)","No nested conditional logic or exceptions","Single compliance requirement with absolute deadline","No cross-references to other legislation or regulations beyond a non-binding note about a manufacturer service bulletin","Straightforward applicability test (aircraft model series only)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nIt orders owners and operators of specific Beagle B121 (Pup) Series 2 and 3 aeroplanes to replace certain throttle cable assemblies with updated, safer versions.\n\n**Who it affects:**\n- Owners and operators of Beagle B121 Series 2 and 3 aircraft\n- Specifically, those with throttle cable part numbers BE.47.20017 (Series 2) or BE.47.30019/1 (Series 3)\n\n**What must be done:**\n- **Series 2 aircraft:** Replace cable P/N BE.47.20017 with P/N BE.47.20037\n- **Series 3 aircraft:** Replace cable P/N BE.47.30019/1 with P/N BE.47.30025\n\n**Deadline:**\nThe replacement must be completed **before 31 May 1978**.\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. They are issued when a design flaw, manufacturing defect, or operational issue is discovered that could affect flight safety. Non-compliance means the aircraft cannot legally fly. This particular directive addresses a specific throttle cable assembly issue that presumably posed a safety risk (though the exact nature of the defect isn't detailed in this excerpt).\n\n**Cross-reference:**\nThe directive notes that Scottish Aviation Service Bulletin No. B121/74 also covers this issue — this is the manufacturer's own technical notice that likely prompted this mandatory directive."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD does not alter the applicability beyond \"All model B121 Series 2 and 3\" and does not add additional aircraft types. It prescribes replacement of specific throttle cable part numbers with specified replacements and sets a compliance date (Requirement and Compliance lines). There is no evidence in this excerpt that the directive expands or narrows scope beyond that mechanical replacement requirement; any further scope change would need to appear in other documents not present here."},"complexity_factors":["Narrow applicability: only Beagle B121 Series 2 and Series 3 aircraft (Applicability line).","Single, prescriptive mechanical action: replace specified P/Ns with specified P/Ns (Requirement line).","Clear, single compliance deadline: 'Before 31 May 1978.' (Compliance line).","No conditional or phased compliance options shown in the excerpt (no alternative compliance or inspection regimes stated).","Cross-reference to a service bulletin for technical details (Note referencing Scottish Aviation SB No. B121/74)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of all Beagle B121 Series 2 and Series 3 aircraft to replace specified throttle cable assemblies with the listed replacement part numbers by 31 May 1978, citing Scottish Aviation Service Bulletin B121/74 for related material. Costs for parts, labour and any downtime fall to the owners/operators. The mandatory replacement changes aircraft configuration and is intended—per the bulletin reference—to address an underlying throttle‑control issue."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bea-121-20-throttle-cable-assembly","history":"/api/acts/ad-bea-121-20-throttle-cable-assembly/history","analysis":"/api/acts/ad-bea-121-20-throttle-cable-assembly/analysis","conflicts":"/api/acts/ad-bea-121-20-throttle-cable-assembly/conflicts","importantCases":"/api/acts/ad-bea-121-20-throttle-cable-assembly/important-cases","documents":"/api/acts/ad-bea-121-20-throttle-cable-assembly/documents"}}